Scenario: You are in a group of infantry against a smaller number of ranged, who have made their way up to a roof (or around an invi wall or to some other normally unreachable area) with a ladder. There is no way to climb the ladder even for shielders because they get one to each side and shoot around the shield, or even worse, "someone" (we do not know who but it almost always was the same type of people) has destroyed the ladder (and if someone tells them to go down they ignore/pretend not to understand) so they are completely unreachable.
That is what EU1 (battle) became with ladders every other village round, so no thank you.
In siege it allowed for ladder bridges straight to flag which made most maps even more "camp flag to have the slightest chance to not get demolished" than they already are, and making every map the same.